Georgy Margvelashvili, an ally of billionaire Bidzina Ivanishvili, the Georgian prime minister, has won a decisive victory in the country's presidential election, exit polls showed on Sunday night.

The little-known former deputy premier's triumph cements the Georgian Dream coalition's grip on power following Mikheil Saakashvili's 10-year rule, although it is unlikely to end political uncertainty in the former Soviet republic.

His victory will put Georgian Dream in charge of both the presidency and the government for the first time, a year after it ousted Mr Saakashvili's cabinet at the polls.

Mr Margvelashvili had between 66.7 per cent to 68 per cent of votes, according to two exit polls.

Both put his nearest rival, David Bakradze, a former parliamentary speaker, on around 20 per cent. Mr Margvelashvili had required only one vote over 50 per cent to secure victory outright and avert a run-off.

"It seems that the picture is clear, and the final results will not be much different from the exit polls," Mr Bakradze said in televised comments.

accepting defeat, he said: "I congratulate Georgy Margvelashvili on his victory. As the leader of the opposition, I will be ready to work with the new president."

A 44-year-old academic brought into government last year as education minister, and then promoted to deputy premier, Mr Margvelashvili owes his rapid rise entirely to Mr Ivanishvili.

His main foreign policy goal is to pursue close ties with the West and Russia, a balance that has long eluded Georgia.

The departure of Mr Saakashvili, who had served the maximum two terms, should ease policy-making after a year of squabbling between him and Mr Ivanishvili, Georgia's richest man.

Constitutional changes will tilt power from the presidency toward the government and parliament, but the president will have a diplomatic role as head of state, and will be commander-in-chief of the armed forces.

Mr Saakashvili, 45, strengthened democracy in Georgia and launched economic reforms after coming to power following the bloodless "rose revolution" in 2003, but lost a five-day war to Russia in 2008 and failed to reform the justice system.